Upright vacuum cleaner with cyclonic airflow

ABSTRACT

A vacuum cleaner includes a first housing defining a cyclonic airflow chamber and a second housing defining a main suction opening that is in communication with an inlet of the cyclonic chamber. A suction source has a suction airstream inlet in communication with an outlet of the cyclonic chamber, and establishes a suction airstream that enters said main suction opening, passes through said cyclonic chamber, and passes to an outlet of said suction source. A substantial portion of particulates entrained in the suction airstream are separated therefrom when said suction airstream moves in a cyclonic fashion through the cyclonic chamber. A main filter assembly, preferably including filter medium comprising polytetrafluoroethylene (PTFE), is located in the cyclonic chamber so that a suction airstream moving from the main suction opening to the inlet of said suction source by way of the cyclonic airflow chamber passes through the filter medium thereof after said airstream moves in a cyclonic fashion within the cyclonic airflow chamber to remove residual particulates from the suction airstream before it leaves the cyclonic chamber. A HEPA filter can be provided to filter the suction airstream exhausted through the outlet of the suction source prior to the airstream being discharged from the vacuum.

This application is a continuation of U.S. Ser. No. 09/900,557 filedJul. 6, 2001 now U.S. Pat. No. 6,463,622, which is a continuation ofU.S. Ser. No. 09/415,363 filed Oct. 8, 1999, now U.S. Pat. No. 6,260,234B1, which is a continuation-in-part of U.S. Ser. No. 09/216,529 filedDec. 18, 1998, now U.S. Pat. No. 6,070,291, which is acontinuation-in-part of U.S. Ser. No. 09/004,999 filed Jan. 9, 1998, nowU.S. Pat. No. 6,003,196.

BACKGROUND OF THE INVENTION

The present invention relates to vacuum cleaners. More particularly, thepresent invention relates to upright vacuum cleaners used for suctioningdirt and debris from carpets and floors.

Upright vacuum cleaners are ubiquitous. They are known to include anupper portion having a handle, by which an operator of the vacuumcleaner may grasp and maneuver the cleaner, and a lower cleaning nozzleportion which travels across a floor, carpet, or other surface beingcleaned. The upper portion is often formed as a rigid plastic housingwhich encloses a dirt and dust collecting filter bag, although the upperportion may simply be an elongated handle with the filter bag, and anexternal cloth bag, being hung therefrom. The cleaning nozzle ishingedly connected to the upper handle portion such that the upperportion is pivotable between a generally vertical upright storageposition and an inclined operative position. The underside of the nozzleincludes a suction opening formed therein which is in fluidcommunication with the filter bag.

A vacuum or suction source such as a motor and fan assembly is enclosedeither within the nozzle portion or the upper portion of the cleaner.The vacuum source generates the suction required to pull dirt from thecarpet or floor being vacuumed through the suction opening and into thefilter bag. A rotating brush assembly is typically provided in proximitywith the suction opening to loosen dirt and debris from the surfacebeing vacuumed.

To avoid the need for vacuum filter bags, and the associated expense andinconvenience of replacing the bag, another type of upright vacuumcleaner utilizes cyclonic airflow, rather than a filter bag, to separatea majority of the dirt and other particulates from the suctionairstream. The air is then filtered to remove residual particulates,returned to the motor, and exhausted.

Such prior cyclonic airflow upright vacuum cleaners have not been foundto be entirely effective and convenient to use. For example, with theseprior cyclonic airflow vacuum cleaners, the process of emptying dust anddirt from the cyclonic chamber dirt collection container has been foundto be inconvenient, and often resulted in the spillage of the cupcontents. Likewise, with these prior units, replacement of the filterelement has not been convenient. Other cyclonic airflow vacuum cleanershave been found to exhaust air which is not free of residualcontaminants. For example, one prior unit filters the airstream after itpasses through the cyclonic chamber, but thereafter passes the airstreamthrough the motor assembly where it is potentially recontaminated by themotor assembly, itself, prior to its being exhausted into theatmosphere.

Because the cyclonic action of such vacuum cleaners does not completelyremove all dust, dirt, and other contaminants from the suctionairstream, it is necessary to include a filter downstream from thecyclonic chamber. As such, prior cyclonic airflow vacuum cleaners haveheretofore included conventional, non-washable filter elements includinga conventional filtering medium to filter the airstream after it passesthrough the cyclonic chamber. These prior filter elements have causedconsiderable difficulties. A conventional filter that is sufficientlyfine to filter the airstream effectively unduly restricts airflow anddecreases the effectiveness of the cyclonic action. On the other hand, acoarse filter does not effectively filter the airstream of residualcontaminants. Further, conventional filter media, such as paper orfibrous media, has been found to clog readily, thereby unduly decreasingairflow rates over time. Thus, a need has been found for a cyclonicairflow vacuum cleaner with an effective filter positioned in thecyclonic chamber for effectively filtering the airstream withoutclogging. Further, a need has been found for such a vacuum cleanerincluding a washable, re-usable filter element from which dirt is easilyextracted.

Accordingly, it has been deemed desirable to develop a new and improvedupright vacuum cleaner that would overcome the foregoing difficultiesand others while providing better and more advantageous overall results.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, an uprightvacuum cleaner includes an upright housing and a nozzle base hingedlyinterconnected with the upright housing. The nozzle base includes a mainsuction opening in its underside. A cyclonic airflow chamber is definedin the upright housing and is adapted for separating dust and dirt froma cyclonically circulating suction airstream. The main suction openingis in fluid communication with the cyclonic airflow chamber. A suctionsource is located in the upright housing or nozzle base and has asuction airflow inlet in fluid communication with the cyclonic chamber,and also includes a suction airflow outlet. A main filter assembly islocated in the cyclonic chamber upstream from the suction source forfiltering dust and dirt from a suction airstream that passes through thecyclonic airflow chamber. The main filter element extends upwardlywithin the cyclonic airflow chamber from a floor of a dirt containerportion of said housing that defines a lower portion of the cyclonicairflow chamber and that is adapted for receiving and retaining dirt anddust separated from the suction airstream. A conduit depends into thecyclonic airflow chamber from an upper wall of the housing, and theconduit is axially aligned and mates with an upper end of the mainfilter assembly whereby the main filter assembly and the conduittogether define a hollow column structure in the cyclonic airflowchamber.

In accordance with another aspect of the present invention, a vacuumcleaner comprises a first housing member defining a cyclonic airflowchamber adapted for separating entrained dirt and dust from acirculating airstream, and a second housing member defining a mainsuction opening. A first conduit fluidically connects the main suctionopening to an inlet of the cyclonic airflow chamber. A suction sourcehas a suction airstream inlet and a suction airstream outlet, and it isadapted for generating and maintaining a suction airstream flowing fromthe inlet downstream to the outlet. A second conduit fluidicallyconnects an outlet of the cyclonic airflow chamber to the suctionairstream inlet of the suction source. A main filter assembly includes afilter medium comprising a selectively permeable plastic material, andthe main filter assembly is located in the cyclonic chamber so that asuction airstream moving from the main suction opening to the inlet ofthe suction source by way of the cyclonic airflow chamber passes throughthe filter medium after the airstream moves in a cyclonic fashion withinthe cyclonic airflow chamber.

In accordance with still another aspect of the present invention, avacuum cleaner apparatus includes a nozzle defining a main suctionopening, and a main suction source in communication with the mainsuction opening. The main suction source is adapted for establishing asuction airstream that moves into the main suction opening anddownstream into the suction source. A cyclonic chamber is placed incommunication with and between the main suction opening and the suctionsource, and the cyclonic chamber is adapted for imparting a cyclonicflow to the suction airstream whereby a portion of particulatesentrained in the suction airstream are separated therefrom, leavingresidual particulates entrained in the suction airstream. A filterassembly is located in the cyclonic chamber and includes a filtermembrane placed in covering relation with an outlet of the cyclonicchamber. Residual particulates entrained in the suction airstream areblocked from exiting the cyclonic chamber by the filter membrane, andthe filter assembly adapted for being selectively removed from thecyclonic chamber, washed to remove particulates from the membrane, andreplaced in the cyclonic chamber for further filtering operations.

In accordance with yet another aspect of the present invention, a vacuumcleaner comprises a housing defining a cyclonic airflow chamber forseparating contaminants from a suction airstream. The housing furtherdefines a suction airstream inlet and a suction airstream outlet influid communication with the cyclonic airflow chamber. A nozzle baseincludes a main suction opening fluidically connected with the cyclonicairflow chamber inlet. An airstream suction source has an inletfluidically connected to the cyclonic airflow chamber outlet and asuction source exhaust outlet. The suction source selectivelyestablishes and maintains a suction airstream from the nozzle mainsuction opening to the suction source exhaust outlet. A main filterassembly is positioned in fluid communication between the cyclonicairflow chamber and the suction source and is adapted for filteringresidual contaminants from the suction airstream downstream relative tothe cyclonic airflow chamber. The main filter assembly comprising apolymeric filter membrane.

One advantage of the present invention is the provision of a new andimproved vacuum cleaner.

Another advantage of the invention is found in the provision of a vacuumcleaner with a cyclonic airflow chamber through which the suctionairstream flows for separating dust and dirt from the airstream and fordepositing the separated dust and dirt into an easily and convenientlyemptied dirt cup.

Still another advantage of the present invention resides in theprovision of a cyclonic airflow upright vacuum cleaner with a mainfilter that effectively filters residual contaminants from the suctionairstream between the cyclonic airflow chamber and the motor assemblywithout unduly restricting airflow and without premature clogging. Yetanother advantage of the invention is the provision of a cyclonicairflow upright vacuum cleaner with a final filter located downstreamfrom the suction motor assembly for filtering the suction airstreamimmediately prior to its exhaustion into the atmosphere.

A further advantage of the invention is the provision of a vacuumcleaner with a main filter, an auxiliary filter, and a final filterwherein the main, auxiliary, final filters are easily removable andreplaceable.

A still further advantage of the present invention is the provision of avacuum cleaner with a cyclonic airflow chamber and main filter element,wherein the main filter element is positioned in a removable dirt cuppartially defining the cyclonic airflow chamber for ease of emptying thedirt cup and cleaning the filter.

A yet further advantage of the present invention resides in theprovision of a vacuum cleaner with a cyclonic airflow chamber and a mainfilter assembly situated in the cyclonic airflow chamber, wherein themain filter assembly includes a re-usable filter element that is easilyand repeatedly cleanable by washing.

Still other benefits and advantages of the invention will becomeapparent to those skilled in the art upon reading and understanding thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take form in certain components and structures,preferred embodiments of which will be illustrated in the accompanyingdrawings wherein:

FIG. 1 is a perspective view illustrating a cyclonic airflow uprightvacuum cleaner in accordance with the present invention;

FIG. 2 is a front elevational view of the vacuum cleaner illustrated inFIG. 1;

FIGS. 3 and 4 are left and right side elevational views, respectively,of the vacuum cleaner shown in FIG. 1;

FIG. 5 is a rear elevational view of the vacuum cleaner of FIG. 1;

FIG. 6 is a bottom plan view of the vacuum cleaner of FIG. 1;

FIG. 7 is a front elevational view of the upright housing portion of thevacuum cleaner of FIG. 1;

FIG. 8 is a perspective view of the final filter assembly in accordancewith the present invention;

FIG. 9 is a side elevational view in cross-section of a vacuum cleanerwith cyclonic airflow in accordance with a preferred embodiment of thepresent invention showing suction airflow through the cyclonic airflowdust and dirt separating chamber;

FIG. 10 is an exploded perspective view of an upper housing member andassociated depending upper conduit of the vacuum cleaner of FIG. 9;

FIG. 11 is a cross-sectional view of the assembled upper housing memberand conduit of FIG. 10;

FIG. 12 is a perspective view of the upper conduit of FIG. 10;

FIG. 13 is an exploded perspective view of a dirt cup, main filterassembly, and filter mount means as employed in the vacuum cleaner ofFIG. 9;

FIG. 14 is a rear elevational view of the dirt cup, main filterassembly, and filter mount means of FIG. 13 in an assembled condition;

FIG. 15 is a rear elevational view of a preferred main filter assemblyformed in accordance with the present invention; and,

FIG. 16 is a view taken along line A—A of FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the FIGURES, wherein the showings are for purposes ofillustrating a preferred embodiment of the invention only and not forpurposes of limiting the same, FIGS. 1-6 illustrate an upright vacuumcleaner A including an upright housing section B and a nozzle basesection C. The sections B,C are pivotally or hingedly connected throughthe use of trunnions or another suitable hinge assembly D so that theupright housing section B pivots between a generally vertical storageposition (as shown) and an inclined, operative position. Both theupright and nozzle sections B,C are preferably made from conventionalmaterials such as molded plastics and the like. The upright section Bincludes a handle 20 extending upward therefrom by which an operator ofthe vacuum A is able to grasp and maneuver the vacuum.

During vacuuming operations, the nozzle base C travels across the floor,carpet, or other subjacent surface being cleaned. The underside 24 (FIG.6) of the nozzle base includes a main suction opening 26 formed thereinthat extends substantially across the width of the nozzle base C at thefront end thereof, the main suction opening 26 is in fluid communicationwith the vacuum upright body section B through a passage 30 and aconnector hose assembly 34 (see also FIG. 5) or a like conduit. Arotating brush assembly 36 is positioned in the region of the nozzlemain suction opening 26 for contacting and scrubbing the surface beingvacuumed to loosen embedded dirt and dust. A plurality of wheels 38support the nozzle base on the surface being cleaned and facilitate itsmovement thereacross.

The upright vacuum cleaner A includes a vacuum or suction source forgenerating the required suction airflow for cleaning operations. Withreference particularly to FIGS. 5 and 9, a suitable suction source, suchas an electric motor and fan assembly E, generates a suction force in asuction inlet 40 and an exhaust force in an exhaust outlet 42. Theexhaust outlet 42 of the motor assembly is in fluid communication with adownstream final filter assembly F for filtering residual contaminantsfrom the airstream exhausted by the motor assembly immediately prior todischarge of the exhaust airstream into the atmosphere. The suctioninlet 40 of the motor assembly E is in fluid communication with anupstream elongated suction conduit 46 that extends upwardly from themotor/fan assembly E to an upper region of the upright section B whereit communicates with the cyclonic suction airflow dust and dirtseparating region G of the vacuum A to generate a suction force therein.

With reference now particularly to FIGS. 7 and 9, the cyclonic suctionairflow dust and dirt separating region G housed in the upright sectionB includes and is defined by an upper housing assembly 50 and a matingdust and dirt cup or container 52. These sections 50,52 together definea generally cylindrical cyclonic airflow chamber 54. The upper housingsection 50 includes a suction airflow outlet passage 60 thatcommunicates with the cyclonic chamber 54 through an aperture 62. Theoutlet passage 60 also communicates with the motor/fan assembly E by wayof the elongated suction conduit 46. FIG. 9 shows that the elongatedsuction conduit 46 extends from the motor/fan assembly E upward tocommunicate with the upper housing suction outlet passage 60 so that thesuction inlet of the motor/fan assembly E is able to fluidicallycommunicate with the cyclonic chamber 54. It is preferred that theaperture 62 be centrally located in the cyclonic chamber 54.

The dirt cup or container 52 defining the lower portion of the cyclonicairflow dust and dirt separating chamber 54 is constructed for largecapacity and ease of emptying the contents as necessary. The dirtcontainer 52 defines over half the total volume of the cyclonic chamber54. The capacity of the container 52 is maximized to lengthen theoperational time before the dirt container 52 must be emptied.Furthermore, the dirt container 52 is preferably at least partiallytransparent so that an operator of the vacuum is able to view the levelof dirt and dust L accumulated therein for purposes of determining whenthe container should be emptied.

The dirt container 52 is connected to the vacuum upright section Bthrough use of a hinge assembly 90 that allows the dirt container 52 topivot (as indicated by the arrow P) between the illustrated closed,operative position and an open forwardly tilted position. Once the dirtcontainer 52 is pivoted into its open position, it may be pulled upwardand away from the section B and separated therefrom for ease of emptyingthe dirt container. A handle 96 is provided on the exterior of thecontainer 52 to facilitate operator movement of the container betweenthe open and closed positions, and a resiliently biased latch 98 retainsthe dirt container in the closed position for vacuuming operations.

The dirt container upper edge 100 defining an open upper end of thecontainer 52 is preferably inclined downwardly in the direction awayfrom the handle 96 or front of the container 52. The upper housingsection 50 is formed with a complimentary mating inclined lower edge102, and a seal such as a gasket or other structure (not shown) ispreferably provided between the edges 100,102 to prevent air leakageinto the cyclonic airflow chamber 54. The inclined upper edge 100 of thedirt container 52 also ensures that, when the container is pivoted tothe open position, the upper edge 100 lies in a substantially horizontalplane. Therefore, the contents of the container are much less likely tospill when the container is opened during emptying operations.Preferably, the angle at which the upper edge 100 is inclined fromhorizontal is selected, in combination with the maximum distance thecontainer is able to be pivoted on the arc P when opened, such that whenthe container is fully opened, the upper edge lies in a substantiallyhorizontal plane.

The dirt cup 52 is shown in further detail in FIGS. 13 and 14. Itincludes a main filter support such as a post, stem, or like structure150 projecting upwardly from a floor or base 152. The floor 152 of thefilter support also defines the floor of the dirt cup 52 when the mainfilter support is seated and suitably secured in the dirt cup. When themain filter support is operatively positioned in the dirt cup 52, thepost 150 is centrally positioned in the cyclonic airflow chamber 54defined by the upper housing member 50 and the dirt cup 52 on a centralaxis 81.

A hollow, cylindrical main filter assembly K is positioned over the mainfilter support 150. The filter assembly K is engaged in an interferencefit with vanes 154 and/or a disc-like plateau or boss 156 located on thefloor 152 of the filter support so that the filter assembly K isreleasably, yet securely, retained in its operative position as shownherein, even when the dirt cup 52 is removed from the vacuum cleaner andinverted for purposes of emptying the contents thereof. An upper filterring 158, accommodating a gasket 159, is provided along the uppermostedge of a main filter medium membrane 180, and the main filter assemblyK extends upwardly from the floor 152 to a level approximately equal toan upper edge 100 of the dirt cup 52. Most preferably, the uppermostedge of the main filter assembly K as defined by the ring 158 is alsosloped in the same manner as is the dirt cup upper edge 100. Over theentire height of the dirt cup 52, an annular cyclonic airflow passage isdefined between the main filter assembly K and the surrounding portionof the dirt cup 52.

A preferred embodiment of the main filter assembly K is illustrated infurther detail in FIGS. 15 and 16. The main filter medium membrane 180is defined in a hollow, tubular, cylindrical form from a planar, pleatedfilter membrane. An upper end of the pleated membrane 180 is seated inan annular groove 184 defined by the upper filter ring 158. Likewise, alower end of the pleated filter membrane 180 is seated in an annulargroove 186 defined by a lower filter ring 157. The rings 157,158 arepreferably defined from molded plastic, and the lower ring 157 definesan aperture 188 that closely receives the boss 156 projecting from thefilter support floor 152 with a tight, friction fit. The upper filterring 158 is conformed in a manner so that, when the dirt cup 52 is inits closed position, the gasket 159 mates in a fluid-tight manner withthe entire peripheral extent of the lowermost edge 166 of an upperconduit 160 (FIG. 9) depending into the cyclonic chamber 54 from theupper housing member 50 so as to prevent undesired airflow through anaxial space between the depending conduit 160 and the filter assembly K.The pleated filter membrane 180 is internally supported on an open framestructure 182 that extends axially between and interconnects the lowerand upper filter rings 157,158. The open frame structure 182 does notimpede airflow through the pleated filter element 180, but ensures thatthe filter element will not collapse under the force of the suctionairstream J.

A preferred medium for the filter membrane 180 comprisespolytetrafluoroethylene (PTFE), a polymeric, plastic material commonlyreferred to by the registered trademark TEFLON®. The low coefficient offriction of a filter medium comprising PTFE facilitates cleaning of thefilter element by washing. Most preferably, the pleated filter medium180 is defined substantially or entirely from GORE-TEX®, a PTFE-basedmaterial commercially available from W. L. GORE & ASSOCIATES, Elkton,Md. 21921. The preferred GORE-TEX® filter medium, also sold under thetrademark CLEANSTREAM® by W. L. GORE & ASSOCIATES, is an expanded PTFEmembrane defined from billions of continuous, tiny fibrils. The filterblocks the passage of at least 99% of particles 0.3 μm in size orlarger. Although not visible in the drawings, the inwardly and/oroutwardly facing surface of the CLEANSTREAM® filter membrane 180 ispreferably coated with a mesh backing material of plastic or the likefor durability since it enhances the abrasion-resistance characteristicsof the plastic filter material. The mesh may also enhance the strengthof the plastic filter material somewhat.

Referring now also to FIGS. 10-12, the relationship of the upper housingmember 50 and the depending upper conduit 160 is described. The conduit160 projects centrally downwardly into the chamber 54 from a top wall162 of the housing member 50. The upper conduit 160 is preferably ahollow cylindrical member with a bore 164 extending therethrough. Thebore 164 is in fluid communication with the suction airstream outletpassage 60 through which the suction airflow J exits the cyclonicairflow chamber 54. The conduit 160 projects downwardly from the housingtop wall 162 so that the lowermost edge 166 thereof is approximatelyequal to the level of the lower edge 102 of the housing ember 50. Also,the lower edge 166 is sloped in a manner that corresponds to the slopeof the housing member lower edge 102. The upper conduit 160 is connectedto the upper housing member 50 by any suitable means such as fastenersengaged in aligned bores 168 a, 168 b (FIG. 10) respectively formed inthe housing member 50 and conduit 160. As mentioned, the gasket 159 isprovided along the joint between the lowermost edge 166 of the upperconduit 160 and the upper edge of the filter assembly K.

With reference now specifically to FIG. 12, an auxiliary filter supportgrid or framework 170 is provided and extends across the bore 164,preferably in the region of the conduit lower edge 166. The open filtersupport 170 provides a backing member for a foam, paper, or similarconventional auxiliary filter element 174 that removes any residual dustand dirt from the suction airstream J prior to its exit from thecyclonic airflow chamber 54 through the bore 164 and outlet passage 60.In case there is a break in the seal between the filter assembly K andthe conduit 160, the auxiliary filter 174 will prevent dirt or dust frombeing sucked into the motor/fan assembly E of the vacuum cleaner A. Oneor more tabs or teeth 176 project radially inwardly from the conduit 160in the region of the framework 170 to engage the auxiliary filterelement 174 so that the filter element is secured adjacent the framework170 and will not be dislodged from its operative position by the forceof gravity.

As is most readily apparent in FIG. 9, the main filter assembly K andthe upper conduit 160 together define a hollow cylindrical columnextending through the center of the cyclonic airflow chamber 54 entirelybetween the floor 152 and top wall 162. This preferred cylindricalcolumnar shape also results from the main filter assembly K and theupper conduit 160 having substantially the same outside diameter.

The suction airstream J established and maintained by the motor/fanassembly E enters an upper portion of the cyclonic dust and dirtseparation chamber 54 through a generally tangential or offset suctionairstream inlet 80 that is preferably horizontally oriented. In thepreferred embodiment, as may be seen most clearly with reference toFIGS. 10 and 11, the cyclonic chamber airstream inlet 80 is formed inthe upper housing member 50, and it is noted that the inlet 80 isdisposed entirely on one side of a centerline 81 of the upper housingsection so as to induce a swirling flow in the chamber 54. As shown inFIG. 5, the suction airstream inlet 80 is in fluid communication with asuction airstream hose 82 through a fitting 84, and the airstream hose82 is, itself, fluidically connected with the main suction opening 26formed in the underside of the nozzle base C by way of the conduit 34and a fitting 86. As such, the main suction opening 26 is in fluidcommunication with the cyclonic chamber 54 through the passage 30, thehoses 34,82, and the cyclonic chamber suction inlet 80.

The vacuum A also comprises a final filter assembly F (see e.g., FIGS.1-3 and 5) adapted for filtering the suction airstream downstream fromthe motor/fan assembly and immediately prior to its exhaustion into theatmosphere. A preferred structure of the final filter assembly F isillustrated most clearly in FIG. 8 and comprises a suction airstreaminlet 120 which is connected downstream and in fluid communication withthe exhaust outlet 42 of the motor and fan assembly E. The inlet 120communicates with an elongated plenum 122 that opens to the atmosphereand houses a filter medium. A protective grid or grate structure 124 issnap-fit or otherwise effectively secured over the plenum 122 to securethe filter medium in place. The filter medium is preferably a highefficiency particulate arrest (HEPA) filter element in a sheet or blockform. The filter medium is retained in position in the plenum by thegrid 124, but is easily replaced by removing the grid. As such, thoseskilled in the art will recognize that even if the motor/fan assemblycauses contaminants to be introduced into the suction airstreamdownstream from the main filter element H, the final filter assembly Fwill remove the same such that only contaminant-free air is dischargedinto the atmosphere.

Referring now primarily to FIGS. 5 and 9, the operation of the vacuumcleaning apparatus A is illustrated, with the flow of the suctionairstream indicated by use of arrows J. The motor/fan assembly E orother suction generator establishes a suction force at its suction inlet40, in the elongated suction conduit 46, and thus in the cyclonicseparation chamber 54. This suction force or negative pressure in thechamber 54 is communicated to the main suction opening 26 formed in thenozzle underside 24 through the hoses 82,34 and associated fittings.This, then, in combination with the scrubbing action of the rotatingbrush assembly 36 causes dust and dirt from the surface being cleaned tobe entrained in the suction airflow J and pulled into the upper portionof the chamber 54 through the generally tangential inlet 80.

As the suction airstream J enters the cyclonic chamber 54 through theinlet 80, it travels downwardly in a cyclonic fashion so that a portionof the dust and dirt entrained in the suction airstream are separatedtherefrom and collected in the dirt cup 52 (as indicated at L). Thesuction airstream J then passes through the main filter assembly K toremove residual contaminants therefrom, and moves upwardly through themain filter element K, through the auxiliary filter element 174, andinto the bore 164 of the depending conduit 160. The airstream J isprevented from bypassing the main filter element K by the gasket 159positioned axially between the filter assembly K and the conduit 160.The airstream J then exits the cyclonic airflow chamber 54 through theoutlet passage 60 and moves downwardly through the conduit 46 to theinlet 40 of the motor/fan assembly E and is then exhausted through themotor exhaust outlet 42 to the final filter assembly F where it isfiltered again by the HEPA filter to remove any contaminants that passedthrough the chamber 54, the main filter assembly K, the auxiliary filter174, and also any contaminants introduced into the airstream by themotor/fan assembly E, itself.

The position of the main filter assembly K, extending upwardly from thefloor 152, is highly desirable given that, as dust and dirt L arecollected, at least a portion M of the suction airstream passes throughthe accumulated dust and dirt L. The accumulation of dust and dirt Lseems to act as yet another filter element which filters more dust anddirt from the airstream M. Also, the flow of the suction airstream Mdownwardly through the accumulated dust and dirt L acts to compact thedust and dirt L downwardly toward the floor 152 so that the capacity ofthe dirt cup 52 is efficiently utilized to extend the time before thedirt cup must be emptied. As noted, a main advantage of the presentinvention is that the main filter assembly K can be cleaned by washingit, either manually or in a dishwasher—since it is dishwasher-safe—toremove dust or dirt particles adhering to the filter element.

The orientation of the inlet 80 will affect the direction of cyclonicairflow, and the invention is not meant to be limited to a particulardirection, i.e, clockwise or counterclockwise. Those skilled in the artwill certainly recognize that the term “cyclonic” as used herein is notmeant to be limited to a particular direction of airflow rotation. Thiscyclonic action separates a substantial portion of the entrained dustand dirt from the suction airstream and causes the dust and dirt to bedeposited in the dirt cup or container.

The invention has been described with reference to the preferredembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the invention be construed as includingall such modifications and alterations insofar as they come within thescope of the appended claims or the equivalents thereof.

What is claimed is:
 1. An upright vacuum cleaner comprising: an uprighthousing comprising: a dirt separation chamber for separatingcontaminants from an airstream, said dirt separation chamber includingan airstream inlet and an airstream outlet, and a dirt cup selectivelyremovable from a socket defined in said upright housing, said dirt cupcommunicating with said dirt separation chamber; a nozzle base pivotablyconnected to said upright housing and including a main suction opening,said main suction opening being fluidically connected with said dirtseparation chamber; an airstream source for generating a cyclonic flowof the airstream in the dirt separation chamber; and, a selectivelyremovable main filter assembly disposed in the dirt separation chamberto cover said airstream outlet, and wherein said cyclonic flow of theairstream circulates about at least a portion of said main filterassembly prior to said airstream exiting said chamber.
 2. The uprightvacuum cleaner of claim 1 wherein said dirt cup comprises a handle. 3.The upright vacuum cleaner of claim 1 wherein said airstream source islocated below said dirt separation chamber.
 4. The upright vacuumcleaner of claim 1 further comprising: a hinge operative to pivotablyconnect said upright housing and said nozzle base.
 5. The upright vacuumcleaner of claim 4 wherein said airstream source is disposed adjacent tosaid hinge.
 6. The upright vacuum cleaner of claim 1 wherein said filterassembly comprises an open frame structure operative to support a filterelement of said filter assembly.
 7. The upright vacuum cleaner of claim6 wherein said filter element comprises a thermoplastic material.
 8. Anupright vacuum cleaner comprising: a base portion; a rotating brushassembly included in the base portion; an upright housing sectionhingedly connected to the base portion; a cyclonic separator located insaid upright housing section, the cyclonic separator having a tangentialinlet and an outlet, and wherein an airflow in the cyclonic separatorcomprises a cyclonically flowing airstream; a suction source forgenerating the airflow; a dirt cup selectively mounted to said uprighthousing section and communicating with said cyclonic separator; and, afilter assembly disposed in the upright housing above the suctionsource.
 9. The upright vacuum cleaner of claim 8 further comprising aconduit interconnecting the outlet with the suction source.
 10. Theupright vacuum cleaner of claim 8 wherein the upright housing sectioncomprises a socket for receiving the dirt cup.
 11. The upright vacuumcleaner of claim 8 further comprising an auxiliary filter fluidicallydisposed between the cyclonic separator outlet and the suction source.12. The upright vacuum cleaner of claim 8 further comprising a finalfilter fluidically disposed to filter air received from an exhaust sideof the suction source.
 13. The upright vacuum cleaner of claim 8 whereinthe filter assembly comprises an open frame structure operative tosupport a filter element of the filter assembly.
 14. The upright vacuumcleaner of claim 8 wherein the filter assembly includes a filter elementthat comprises a thermoplastic material.
 15. A vacuum cleanercomprising: a removable dirt cup; a cyclonic chamber communicating withthe dirt cup, the cyclonic chamber including an air flow inlet and anair flow outlet; a first housing member holding the cyclonic chamber,said first housing member comprising a socket for selectively receivingthe dirt cup; a main suction opening connected to the first housingmember and communicating with the air flow inlet of the cyclonicchamber; an airstream drive having an airstream inlet and an airstreamoutlet; a conduit for fluidically connecting the air flow outlet of thecyclonic chamber to the airstream inlet of the airstream drive; and, amain filter assembly disposed in the cyclonic chamber so that anairstream moving from said air flow inlet of said cyclonic chamber tothe airstream inlet of the airstream drive passes through said mainfilter assembly.
 16. The vacuum cleaner as set forth in claim 15 whereinthe main filter assembly comprises a cylindrical filter element.
 17. Thevacuum cleaner as set forth in claim 16 herein the filter element issupported on an internal open framework cylindrical support structure.18. The vacuum cleaner as set forth in claim 15 wherein the dirt cup isheld in place within the housing by a releasable latch.
 19. The vacuumcleaner as set forth in claim 15 wherein the air flow inlet ishorizontally oriented and arranged so that the airstream flowing throughthe air flow inlet flows around the main filter assembly.
 20. The vacuumcleaner as set forth in claim 19 further comprising: an auxiliary filterlocated upstream relative to the airstream inlet of the airstream driveand downstream relative to the main filter assembly, the auxiliaryfilter adapted for filtering residual contaminants from the airstreamexiting the cyclonic chamber prior to the residual contaminants enteringsaid airstream inlet of said airstream drive.
 21. A vacuum cleanercomprising: a removable dirt cup; a cyclonic chamber communicating withthe dirt cup, the cyclonic chamber including an air flow inlet and anair flow outlet; a first housing member holding the cyclonic chamber andselectively receiving the dirt cup; an airstream drive having anairstream inlet and an airstream outlet, the airstream drive operativeto generate and maintain the airstream flowing from the airstream inletto said airstream outlet, said airstream drive being located in saidfirst housing member beneath said dirt cup; and, a main filter assemblydisposed in the cyclonic chamber so that the airstream moving from saidair flow inlet of the cyclonic chamber to the airstream inlet of theairstream drive passes through the main filter assembly after at least aportion of entrained dirt in the airstream is separated therefrom bycyclonic airflow.
 22. The vacuum cleaner as set forth in claim 1 whereinthe main filter assembly comprises a cylindrical filter element.
 23. Thevacuum cleaner as set forth in claim 21 wherein the filter element issupported on an internal open framework cylindrical support structure.24. The vacuum cleaner as set forth in claim 21 wherein the dirt cup isheld in place within said housing member by a releasable latch.
 25. Thevacuum cleaner as set forth in claim 1 wherein the air flow inlet of thecyclonic chamber is horizontally oriented and arranged so that theairstream flowing through said inlet flows around said main filterassembly.
 26. The vacuum cleaner as set forth in claim 21 furthercomprising: an auxiliary filter located upstream relative to theairstream inlet and downstream relative to the main filter assembly, theauxiliary filter adapted for filtering residual contaminants from anairstream exiting the cyclonic chamber prior to said residualcontaminants entering the airstream inlet of the airstream drive. 27.The vacuum cleaner as set forth in claim 21 further comprising: a finalfilter located downstream relative to the airstream outlet, the finalfilter adapted for filtering remaining contaminants from an airstreamexiting the airstream drive.